RFI from fuel pump
 

I've got a Mazda Tribute (near replica of the Ford Escape) and have the
dreaded RFI from the electric fuel pump. I've done a ton of research
on the Internet and determined that the most popular option for
resolving the issue is to install a RFI filter on the pump. This
involves dropping the tank, which is beyond my capability. So, to do
the install will involve a trip to the dealership, costing around $200
for parts/installation.

I've also seen a homebrew ferrite filter that can be installed at the
power lead for the fuel pump, which is an option.

But, I did see one posting where a guy resolved the problem by
upgrading to a K40 antenna, which he said filtered the RFI. So, I'm
wondering if anyone has had success eliminating fuel pump RFI with a
good antenna? I'm willing to give that a try, but it will probably
involve ordering one, so if there's only a small chance it will work
I'll probably skip this option and go straight for the filter.
Thoughts?

On 2 Jan 2005 10:22:21 -0800, wrote in
. com:

I've got a Mazda Tribute (near replica of the Ford Escape) and have the
dreaded RFI from the electric fuel pump. I've done a ton of research
on the Internet and determined that the most popular option for
resolving the issue is to install a RFI filter on the pump. This
involves dropping the tank, which is beyond my capability. So, to do
the install will involve a trip to the dealership, costing around $200
for parts/installation.

I've also seen a homebrew ferrite filter that can be installed at the
power lead for the fuel pump, which is an option.

But, I did see one posting where a guy resolved the problem by
upgrading to a K40 antenna, which he said filtered the RFI. So, I'm
wondering if anyone has had success eliminating fuel pump RFI with a
good antenna? I'm willing to give that a try, but it will probably
involve ordering one, so if there's only a small chance it will work
I'll probably skip this option and go straight for the filter.
Thoughts?


Three questions, if you don't mind:

1. How is your radio mounted and grounded?

2. Are you using power from the lighter socket?

3. What kind of antenna you you have now?

Pull the carpet up inside the vehicle above the fuel tank and see if
there's an access plate to get to the pump..

Some cars have one.

-SSB

wrote:
I've got a Mazda Tribute (near replica of the Ford Escape) and have the
dreaded RFI from the electric fuel pump. I've done a ton of research
on the Internet and determined that the most popular option for
resolving the issue is to install a RFI filter on the pump. This
involves dropping the tank, which is beyond my capability. So, to do
the install will involve a trip to the dealership, costing around $200
for parts/installation.

I've also seen a homebrew ferrite filter that can be installed at the
power lead for the fuel pump, which is an option.

But, I did see one posting where a guy resolved the problem by
upgrading to a K40 antenna, which he said filtered the RFI. So, I'm
wondering if anyone has had success eliminating fuel pump RFI with a
good antenna? I'm willing to give that a try, but it will probably
involve ordering one, so if there's only a small chance it will work
I'll probably skip this option and go straight for the filter.
Thoughts?

1. It's mounted using a standard RS bracket within a plastic
compartment on the console.

2. No, powered from the fusebox.
3. Grounded to a bolt on the door hinge.

Sideband, unfortunately the fuel pump is located within the tank.

On 2 Jan 2005 11:15:17 -0800, wrote in
.com:

1. It's mounted using a standard RS bracket within a plastic
compartment on the console.

snip

3. Grounded to a bolt on the door hinge.


Seems you have a floating (ungrounded) system. DC ground is not the
same as RF ground, the latter needing as short a wire as possible. In
fact, the antenna base should be mounted directly to some bodywork and
you can't cheat by running a wire to a ground somewhere else. The same
should be done with the radio if possible, although a -very- short
wire from the radio to ground (the deck beneath the console) should be
OK as long as your antenna mount is well grounded.

The reason RF grounding is so important is because a floating system
picks up noise very easily. Also, the antenna works much better when
properly installed. You can gain 2-3 S-units (and increase your
transmit range proportionately) by properly mounting the antenna. I've
installed lots of CB and commercial radios and as long as everything
is grounded (RF ground) there is rarely a problem with RFI..... unless
the alternator is going bad or something like that, but you would be
able to hear that in your AM/FM radio, too.

It's either that or drop the tank.

This is good advice... really all you would need is one 0.1UF from the
positive to ground. Like he said... close to the pump.

Professor
www.telstar-electronics.com


I have yet to see any Ford's resolved in this manor, the fix is
adding a
couple .1 disc caps at the fuel pump 12v leads, bare the wire close
to
the pump as possible, solder the caps across the + and - wire, and
from +
to chassis ground and ground wire to chassis ground. 2 on each should
do
the trick. You dont have to drop the tank to do this just get wires
as
close to pump as possible.

I heard on my scanner on a 2 meter repeater some guy was fighting with
Ford for the same problem.
Not sure what Ford they were talking about. Ford did the fix,
unfortunately I don't remember what that was. Sorry about that.
I heard it a few months ago. The owner of the car is still fighting
with Ford on who will pay for it.
Good Luck!!
73
================

wrote:

I've got a Mazda Tribute (near replica of the Ford Escape) and have the
dreaded RFI from the electric fuel pump. I've done a ton of research
on the Internet and determined that the most popular option for
resolving the issue is to install a RFI filter on the pump. This
involves dropping the tank, which is beyond my capability. So, to do
the install will involve a trip to the dealership, costing around $200
for parts/installation.

I've also seen a homebrew ferrite filter that can be installed at the
power lead for the fuel pump, which is an option.

But, I did see one posting where a guy resolved the problem by
upgrading to a K40 antenna, which he said filtered the RFI. So, I'm
wondering if anyone has had success eliminating fuel pump RFI with a
good antenna? I'm willing to give that a try, but it will probably
involve ordering one, so if there's only a small chance it will work
I'll probably skip this option and go straight for the filter.
Thoughts?

I heard on my scanner on a 2 meter repeater some guy was fighting with
Ford for the same problem.
Not sure what Ford they were talking about. Ford did the fix,
unfortunately I don't remember what that was. Sorry about that.
I heard it a few months ago. The owner of the car is still fighting
with Ford on who will pay for it.
Good Luck!!
73
================

wrote:

I've got a Mazda Tribute (near replica of the Ford Escape) and have the
dreaded RFI from the electric fuel pump. I've done a ton of research
on the Internet and determined that the most popular option for
resolving the issue is to install a RFI filter on the pump. This
involves dropping the tank, which is beyond my capability. So, to do
the install will involve a trip to the dealership, costing around $200
for parts/installation.

I've also seen a homebrew ferrite filter that can be installed at the
power lead for the fuel pump, which is an option.

But, I did see one posting where a guy resolved the problem by
upgrading to a K40 antenna, which he said filtered the RFI. So, I'm
wondering if anyone has had success eliminating fuel pump RFI with a
good antenna? I'm willing to give that a try, but it will probably
involve ordering one, so if there's only a small chance it will work
I'll probably skip this option and go straight for the filter.
Thoughts?

I wanted to post a follow-up to this... I ended up building the
homebrew filter and it worked perfectly - totally eliminated the fuel
pump noise. It cost less then twenty bucks in materials and was very
simple to assemble and install. Here's a link to the directions I
followed:

http://97vette.com/sporttrac/rfi_fix/rfi_fix.html

A little specific info if you have a Tribute/Escape: to get to the
power leads, simply remove the driver's side back seat (it slides
forward) and pull back the carpet. There's a small square panel that
easily unscrews to reveal the leads (pink and black). There's plenty
of room within this panel to store the RFI filter. Couldn't be easier!